Measuring photoluminescence spectra of self-assembly array nanowire of colloidal CdSe quantum dots using scanning near-field optics microscopy

2016 ◽  
Vol 09 (03) ◽  
pp. 1650040 ◽  
Author(s):  
Zhongchen Bai ◽  
Licai Hao ◽  
Zhengping Zhang ◽  
Shuijie Qin
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Near Field ◽  
Porous Titanium ◽  
Periodic Array ◽  
Main Peak ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Near Field Optics ◽  
Assembly Method

A novel periodic array CdSe nanowire is prepared on a substrate of the porous titanium dioxide by using a self-assembly method of the colloidal CdSe quantum dots (QDs). The experimental results show that the colloidal CdSe QDs have renewedly assembled on its space scale and direction in process of losing background solvent and form the periodic array nanowire. The main peak wavelength of Photoluminescence (PL) spectra, which is measured by using a 100-nm aperture laser beam spot on a scanning near-field optics microscopy, has shifted 60 nm with compared to the colloidal CdSe QDs. Furthermore, we have measured smaller ordered nanometer structure in thin QDs area as well, a 343-nm periodic nanowire in thick QDs area and the colloidal QDs in edge of well-ordered nanowire.

HIGHLY ORDERED MICRO-ARRAYS OF CdSe QUANTUM DOTS ON CHEMICALLY PATTERNED SUBSTRATES

2009 ◽  
Vol 08 (01n02) ◽  
pp. 119-122
Author(s):  
LI ZHANG ◽  
HUA-YAN SI ◽  
HUA XU ◽  
HAO-LI ZHANG ◽  
YU-QING XIONG
Keyword(s):  
Quantum Dots ◽  
Cadmium Selenide ◽  
Self Assembly ◽  
Microcontact Printing ◽  
Cdse Quantum Dots ◽  
Two Dimensional ◽  
Liquid Interfaces ◽  
Patterned Substrates ◽  
Cdse Qds ◽  
Ordered Arrays

Highly ordered arrays consisting uniform fluorescent cadmium selenide ( CdSe ) quantum dots (QDs) ring or dot structures were obtained by self-assembly of QDs on chemically patterned substrates. In this method, Au substrates with alternating hydrophobic and hydrophilic square patterns are firstly fabricated by microcontact printing, which allows water droplets to condense on the hydrophilic regions to provide two-dimensional template arrays. The CdSe QDs are then assembled at the liquid/liquid interfaces to give uniform micro or nanostructures. The shape and size of the rings and dots can be tailored by controlling the relative evaporation speed of the water and the organic solvents. The obtained nanostructures have ideal topography to avoid substrate-induced fluorescence quenching.

Transparent and Light-Emitting Epoxy Nanocomposites Filled with Dodecylamine-Capped CdSe Quantum Dots

2015 ◽  
Vol 727-728 ◽  
pp. 284-287
Author(s):  
Ling Ling Chen
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Epoxy Matrix ◽  
Visible Region ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Epoxy Nanocomposites ◽  
Light Emitting ◽  
Homogeneous Dispersion ◽  
Carbon Chains

An effective approach was used to disperse CdSe quantum dots (QDs) into epoxy matrix and prepare highly transparent luminescent CdSe–epoxy nanocomposites. Dodecylamine-capped CdSe QDs were obtained through self-assembly of carbon chains of as-synthesized QDs and dodecylamine. It was found that dodecylamine-capped CdSe QDs demonstrate a homogeneous dispersion within epoxy matrix, thus the prepared CdSe–epoxy nanocomposites expressed transparence in the visible region and also light-emitting.

scholarly journals Intense Visible Luminescence in CdSe Quantum Dots by Efficiency Surface Passivation with H2O Molecules

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Hyeoung Woo Park ◽  
Do-Hyung Kim
Keyword(s):  
Heat Treatment ◽  
Quantum Dots ◽  
Quantum Yield ◽  
Surface Passivation ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Effect Of Water ◽  
Visible Luminescence ◽  
Luminescence Efficiency

We have investigated the effect of water (H2O) cooling and heat treatment on the luminescence efficiency of core CdSe quantum dots (QDs). The photoluminescence (PL) quantum yield of the CdSe QDs was enhanced up to ~85%, and some periodic bright points were observed in wide color ranges during the heat treatment of QDs mixed with H2O. The PL enhancement of QDs could be attributed to the recovery of QDs surface traps by unreacted ligands confined within the hydrophilic H2O molecule containers.

Developed one-pot synthesis of dual-color CdSe quantum dots for white light-emitting diode application

2018 ◽  
Vol 6 (12) ◽  
pp. 3089-3096 ◽  
Author(s):  
Sheng Dai ◽  
Cyuan-Bin Siao ◽  
Shu-Ru Chung ◽  
Kuan-Wen Wang ◽  
Xiaoqing Pan
Keyword(s):  
Quantum Dots ◽  
White Light ◽  
Light Emitting Diode ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
One Pot ◽  
Synthetic Process ◽  
Light Emitting ◽  
One Pot Synthesis ◽  
Enhanced Stability

The size and fraction of red and green CdSe QDs can be controlled precisely during the synthetic process, thus manifesting remarkably enhanced stability.

Optimizing electron transfer from CdSe QDs to hydrogenase for photocatalytic H2 production

2019 ◽  
Vol 55 (39) ◽  
pp. 5579-5582 ◽  
Author(s):  
Monica L. K. Sanchez ◽  
Chang-Hao Wu ◽  
Michael W. W. Adams ◽  
R. Brian Dyer
Keyword(s):  
Quantum Dots ◽  
Electron Transfer ◽  
Reduction Potential ◽  
H2 Production ◽  
Cdse Quantum Dots ◽  
Redox Mediators ◽  
Cdse Qds ◽  
Electron Shuttles ◽  
Hydrogenase Enzyme

A series of viologen related redox mediators of varying reduction potential has been characterized and their utility as electron shuttles between CdSe quantum dots and hydrogenase enzyme has been demonstrated.

Switching-on superparamagnetism in diluted magnetic Fe(iii) doped CdSe quantum dots

CrystEngComm ◽  
2020 ◽  
Vol 22 (10) ◽  
pp. 1738-1745 ◽  
Author(s):  
Amar Nath Yadav ◽  
Jasleen K. Bindra ◽  
Narendra Jakhar ◽  
Kedar Singh
Keyword(s):  
Quantum Dots ◽  
Exchange Interaction ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Ferromagnetic Exchange ◽  
Diluted Magnetic ◽  
Weak Ferromagnetic

Chemically prepared, 0.5% Fe(iii)-doped CdSe QDs exhibit superparamagnetism with weak ferromagnetic exchange interaction.

Dependence of Luminescence Efficiency of CdSe Quantum Dots on Chemical Environments

2008 ◽  
Vol 8 (11) ◽  
pp. 5615-5623 ◽  
Author(s):  
Rajan Jose ◽  
Mitsuru Ishikawa ◽  
Velmurugan Thavasi ◽  
Yoshinobu Baba ◽  
Seeram Ramakrishna
Keyword(s):  
Quantum Dots ◽  
Cadmium Acetate ◽  
Trioctylphosphine Oxide ◽  
Cdse Quantum Dots ◽  
Cdse Qds ◽  
Luminescence Efficiency ◽  
Cadmium Stearate

Dependence of photoluminescence (PL) efficiency (ΦPL) of CdSe quantum dots (QDs) on coordinating solvents, precursors, and dispersing solvents was investigated. The ΦPL of CdSe QDs was ∼0.05 when synthesized at 120 °C using the precursors, cadmium acetate (CdAc) and trioctylphosphine selenide (TOPSe) in trioctylphosphine (TOP). The ΦPL was increased from 0.05 to ∼0.1 when coordinating solvents, trioctylphosphine oxide (TOPO) and hexadecylamine (HDA), were added to the above reaction mixture. The ΦPL was dramatically increased from ∼0.1 to ∼0.7 when CdAc was replaced by cadmium stearate (CdSt). The ΦPL of CdSe QDs synthesized using cadmium stearate (CdSt)/TOPSe/TOP/TOPO was measured in butanol, chloroform, hexane, and toluene and found that the ΦPL is strong dispersing solvent-dependent. The DFT analysis at b3lyp/lanl2dz level on the interaction of CdSe QDs with chemical environments showed that oxygen-containing molecules interact strongly with CdSe compared to non-oxygen containing molecules and could influence the ΦPL.

Optimized Synthesis of Water-Soluble and Small-Size CdSe Quantum Dots

2011 ◽  
Vol 266 ◽  
pp. 46-50
Author(s):  
Jiao Yun Xia ◽  
Jun Long Tang
Keyword(s):  
Aqueous Solution ◽  
Quantum Dots ◽  
Water Soluble ◽  
Cdse Quantum Dots ◽  
Key Factors ◽  
Cdse Qds ◽  
High Quality ◽  
Synthesis Route ◽  
Initial Ph

An optimized synthesis route was applied for controlling the preparation of CdSe quantum dots (QDs) in an aqueous solution. Some key factors which influencing the properties of CdSe QDs, such as initial pH, ratio of precursor etc, were investigated. The as-prepared products have been characterized by TEM, XPS, XRD, UV-Vis and fluorescence (FL) spectra. The result showed that the high-quality CdSe QDs with 3 nm was obtained. The experiments also conformed that the CdSe QDs with better FL properties were obtained with properly initial pH, 5, suitably [Cd2+] / [SeSO3 2-], range from 1:0.25 to 1:0.75 and the ratio of [Cd2+] / [TGA] is 1:2~1:3.

Characterization and 2D Self-Assembly of CdSe Quantum Dots at the Air−Water Interface

2005 ◽  
Vol 127 (42) ◽  
pp. 14640-14646 ◽  
Author(s):  
Kerim M. Gattás-Asfura ◽  
Celeste A. Constantine ◽  
Matthew J. Lynn ◽  
Daniel A. Thimann ◽  
Xiaojun Ji ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Self Assembly ◽  
Cdse Quantum Dots ◽  
Water Interface ◽  
Air Water Interface
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